PURPOSE: Generalized peritonitis caused by a free perforation of gastric cancer is a rare condition, which occurs in 1~4% of all gastric cancer patients. To assess the characteristics of the patients and investigate the optimal treatment of choice, the data from 51 patients previous recent 10 years were retrospectively analyzed. METHODS: Between 1988 and 1997, 51 patients underwent surgical treatment for perforated gastric cancer. The clinicopathological features and survival rates of the resected group (n=39) and the non-resected group (n=12) were analyzed. RESULTS: The incidence was 0.78% and the mean age was 57 years. The most common tumor location was in the lower 1/3 in the resected group (n=21, 53.8%) and in the upper 1/3 in the non-resected group (n=6, 50%). Borrmann type 3, the poorly differentiated type, and a positive serosa invasion were more common in both groups. Liver and peritoneal metastases were observed in 2 cases (5.2%) and 7 cases (14.3%) in the resected group, and 4 cases (33.4%), and 3 cases (25%) in the non-resected group, respectively. Resectability found in 76.5%: 27 cases of a subtotal gastrectomy and 12 cases of a total gastrectomy. A limited lymph node dissection (D0, D1) was performed in 14 cases (35.9%) and an extended dissection (D2, D3) was performed in 25 cases (64.1%). The 5-year survival rate of stage I was 80%, 40% in stage II, 14% in stage III and 0% in stage IV, and the overall 5 year survival rate was 20.5% in the resected group and 0% in the non-resected group. The depth of invasion, lymph node metastasis and tumor stage significantly influenced the survival rate of the patients. CONCLUSION: Because a perforation of the gastric cancer may develop in every stage, surgeons must take care of these patients by the same way as with non-perforation cases.